Who wants a MAGROM board?

Everything about Martin Allcorn's Games ROM
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Dave
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Re: Who wants a MAGROM board?

Post by Dave » 18 Dec 2013 14:20

Hi Andy,

not too late though.

As you will have seen from the thread, Martin has continued developing the board which is now at Version 5 of the hardware design. It is pretty well finalised now though and Martin will shortly be producing a revised KiCad schematic, at which point I will redo the PCB design wth a view to getting some made up.

regards
Dave

Martin A
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Joined: 09 Nov 2013 21:03

Re: Who wants a MAGROM board?

Post by Martin A » 05 Jan 2014 18:58

Quick status update:

The software has been developed a little further, there are 38 games on the current rom. To save a little bit of wear on the the expansion connector the rom will now only boot if the space bar is pressed at reset. Without the space bar the MTX will boot to Basic as normal.

Testing of the current software has been done on a MTX500 and a copy is with Dave for testing on a MTX512 (when he has time)

Technical summary.

There's a thread on Facebook at the moment about MTX hardware, ports etc. So I thought I would confirm here the resources that the board used

ROM 7 in the 02000H-03FFFH memory range is used for the boot/loading software
one page 04000H-07FFFH in what is normally the RAM area is occupied by the game data, set by a hardware jumper to match the host machine type.
I/O port 0FFH is used to control which "page" of the game data is visible in this area
2 bytes of high ram are used on boot/loading but no but permanent ram allocation is needed.

There's one unused NAND gate in the current design, if it were vitally important, this could be utilised to invert one bit in the I/O port address (to one of 07FH, 0BFH, 0DFH, 0EFH, 0F7H, 0FBH, 0FDH or 0FEH)

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